Titan's Alien Thunder

An anonymous reader writes "What is not being reported much about the fascinating Huygens descent to the surface of Saturn's largest moon, Titan, is its remarkable microphone. In the silence of space, the probe offers a platform for listening to alien thunder while watching the lightning strike on this alien world--the only moon with an atmosphere thicker than our terrestrial one. The probe detaches from Cassini on Christmas for its atmospheric entry on 14 January 2005. The landing target on Titan borders a bright-dark region thought to be an oil-rich shoreline. Huygens can float for a few hours while still broadcasting if it lands in a lake of oil."

Comments

Re:Alien thunder

[Anonymous Coward]

Isn't oil created by a biological process? How can there be oil on Titan?

Oil?

[Atticka]

Oil? are we talking mineral oil, or the kind that comes from decomposing plant and animal life? I'm no oil expert, but wouldnt that be a sign of alien life?

Re:Oil?

[reverseengineer]

But how come everyone gets excited when methane is detected on a planet like mars for example? Or is it that methane occurs naturally AND is a byproduct of plants/animals?

Well, yes, it does. The reason why finding methane on Mars would be more exciting than methane on Titan is that on Mars, atmospheric methane is not expected to be stable, as it reacts with hydroxyl ions in the presence of sunlight to produce carbon dioxide and water (it should be noted that if the data concerning methane on Mars is right, the concentration is around 10-15 ppb, so don't expect a greenhouse effect and rain clouds any time soon). The methane on Mars would have disappeared within a few hundred years were it not replenished somehow- and the question then, is "How is methane on Mars replenished?"

The two possibilities (and both could be correct) are outgassing from geologic processes or production by methane-producing organisms. Either possibility is actually pretty exciting, as Mars as we know it now is geologically dead- it has the largest volcano in the Solar System, but no evidence of active or recent vulcanism, but of course the possibility that colonies of methanogens similar to terrestrial Archaea are producing methane on Mars would be a much more momentous discovery.

The methane and ethane on Titan, OTOH, has been there for billions of years and is almost certainly from nonliving processes, just as the methane in the atmospheres of the gas giant planets has nothing to do with organisms. It is interesting, still, though, because methane and ethane, gases on earth, may exist as liquid on Titan. A moon larger than Pluto and Mercury with seas of simple organic compounds (and possibly a "snow" of various hydrocarbon and nitrile compounds). A atmosphere denser than earth's composed of 94% nitrogen. Possibly large quanitities of water ice. All definitely reasons to go explore.

Unfortunately, it is extremely unlikely that life has developed on Titan, simply because it is far too cold (about 94K). The basically opaque atmosphere and distance from the sun make really interesting chemistry very difficult, in particular, keeping any water locked up as ice rather than making it available as liquid or vapor. There may be some interesting stuff going on in the upper reaches of the atmosphere, though, as UV breaks down methane and nitrogen gas to produce a variety of polyacetylene and polynitrile compounds which fall as a waxy precipitate (the aforementioned "snow").

The geology of Titan is essentially still a question mark, owing again to the orange-brown veil. If anything like the deep-sea vents of earth exist on Titan, they could provide the rest of the requirements for life- they'd inject heat into the ecosystem, possibly freeing up water vapor and oxygen from the ice, and could provide elements like phosphorus and sulfur (giving the sought-after CHONPS). Also, Saturn produces tremendous tidal forces on Titan. While on the one hand, the development of life on earth was helped substantially by the presence of intertidal areas (which still feature incredible diversity), the tides on Titan may so strong as to quickly erode continental features. There are a lot of mysteries that will be solved after Cassini-Huygens, and no doubt a stack of new ones will be found.

Calling all scientists

[Man in Spandex]

the only moon with an atmosphere thicker than our terrestrial one.

Does a thicker atmosphere necessarely mean a good thing? By good I mean in terms of maybe the life (if any) on the moon/planet or what ressources we may find or conditions of the air?

Re:Calling all scientists

[Anonymous Coward]

The thing that's exciting scientists about Titan is that it's atmosphere is extremely similar to what they believe primordial Earth's atmosphere was like. It's hoped that we may learn something about the origins of life on Earth. The thick atmosphere is a good thing because it means very few elements/gases/etc have burned off or escaped, giving us the chance to study what is the closest thing to "early Earth" as we're ever going to find.

The only moon...

[ArbiterOne]

... with an atmosphere thicker than our moon's that we know of. At the rate science is going... There was a great Arthur. C. Clarke book about hydrogen mining on Titan; I can't remember the title at the moment, but it's definitely worth a read.

Re:Alien thunder

[Timesprout]

I think they are referring to the seas of liquid hydrocarbons suspected to exist on Titan as oil.

Re:Alien thunder

[BWJones]

As I understand it, biological production of oil is one of those long accepted dogmas that may or may not be exclusively true. There is a theory that suggests that oil production may not be biological exclusively. This is supported by a number of meteorites that have fallen to earth containing what appear to be complex hydrocarbon rich complexes. However, all of this said, I seem to remember a recent article in Science or Nature that suggested abiological production of hydrocarbons was possible (as observed in the Canadian shield), but not a significant resource for production of hydrocarbons.

Re:Oil

[eclectro]

By your logic, oil means there is a group of arabs there waiting to fill your tank.

Seriously, oil can form from the complex hydrocarbons present, not just dinosaurs. While controversial, it is though that if this is correct, earth's oil reserves might be larger (and deeper) than previously thought, having come from cosmic sources.

Fuel-breathing jet engines

[G4from128k]

Hydrocarbon-rich atmospheres bring the possibility of fuel-breathing jet engines. With a tank of oxygen or other oxidizer, a craft could scoop the fuel from the "air" and fly or run a powerplant.

Re:For all the NASA jokes...

[grm_wnr]

The topic of TFA, Hyugens, is an ESA project. But you're still right, since the delivery system/orbital probe Cassini is a NASA project. So kudos to NASA, but don't forget the little guys ;)

I wonder

[WormholeFiend]

I wonder if the instruments are going to measure the effects of the sonic boom(s) on entry into Titan's atmosphere too...

Re:Alien thunder

[danudwary]

Though I'm no geochemist, and I've never really sought out dissenting opinions, Thomas Gold's book "The Deep Hot Biosphere" is a pretty interesting and convincing read about the abiogenic oil theory.

Simplistic question

[smooth wombat]

This is definitely a simplistic question and has probably been answered somewhere else in the ether of the web but here goes:

If the probe will be able to float for a few hours IF it lands in a body of some liquid, why did they not include flotation devices like they used to have on the old Apollo capsules? Was it a weight thing (i.e. too much weight), design limitations (i.e. not enough room) a combination thereof or other reasons?

It would seem to me that if the device can float without these devices for several hours then including these devices could extend the floating ability of the probe for days/weeks/months/whatever. This would have substantially increased the time to gather information.

Or are there devices already on the probe and this is the best they could do under the circumstances?

Re:Simplistic question

[DNS-and-BIND]

IF the parachute deploys.

At least they're deploying into liquid, instead of sending the probe into the desert at 350mph.

I dont want to steal their thunder..

[adeyadey]

This is going to be a fascinating event - however I do have some questions.. The total mission cost is around $4 billion - is this good value for money? For example look at New Horizons, a Jupier/Pluto/KBO mission with a total projected cost of $600 million. I also wonder, given the scale of the mission, if a RTG should have been put on board Huygens so that it could stay longer and observe the Titan environment over a longer time? (Yes I know it could only relay data when Cassini passes by, but that could still be useful..) Listening to thunderstorms is all well and good, and adding a mic is worth doing because its a cheap thing to do in such a system, but what about a lander that spends more time there looking at the chemistry of Titan?

I think that the smaller, cheaper missions return much better scientific return for the money. For instance, most of the function of the proposed $10 billion JIMO mission could be done by a cheaper Europa-only orbiter that would cost less than $1 billion. (See: http://www.spacedaily.com/news/hubble-04p.html ) Also take a look at the SMART-1 ESA mission - less than $100 million for a complete mission featuring many new technologies.

For example the camera on the $4 billion Cassini mission is only 1 megapixel - if we had a larger number of smaller, cheaper missions, would we be there now with a much better imaging system. Cassini had a much delayed launch, so the design was outdated by the time of its launch in 1997. The same mission launched on a later window could have used ion propulsion (SEP/RTG combo) saving weight (1/2 the 4 tons Cassini weight is fuel)

The same thing could happen with JIMO - if NASA spend $10 billion on that, they could forego many other missions, such as a New Horizons II mission, which would give us a chance to look at Uranus (not always a good word to say on Slashdot) with modern instruments, as well as Jupiter & some more KBO's..

Also think about Hubble - is it worth spending $2 billion on a robot to repair the aging telescope, when the same money could buy better new space telescopes.. (see link above)

I dont want to belittle the work of the scientist working on Cassini - it will be a fascinating mission, I just wonder if we could get more return by rejigging the beurocracy.. The X-Prize, New Horizons and SMART-1 prove that more smaller & competitive missions return much more bang-per-buck..

Re:I dont want to steal their thunder..

[valkoinen]

The mars photos look great and are large resolution, because they are composite pictures. The rovers hardly move at all and have lots of time to stand still taking photos.

It will be a bit harder to do high quality composite photography when the capsule is falling through alien atmosphere on a parachute into a sea of methane.

Re:Alien thunder

[hb253]

I don't have it in front of me, but one of the articles in this month's Scientific American says that oil on Earth may not necessarily be created from solely biological processes.

Can anyone corroborate if I read it right?

Atmosphere ...

[mikewhittaker]

In fact, there is an Asimov short story in which a character who has spent a long time working on Titan (IIRC) makes a mistake about which gas is flammable/explosive.

Re:Alien thunder

[Rei]

Actually, thinking about it, I was wrong. Oxygen would be a flammable liquid on Titan. :)

Re:For all the NASA jokes...

[nilptr46]

...and of that $95 million goes to DART - a demonstration vehicle that will fly circles around another satellite, snap a couple of pictures, and self destruct 24 hours later.

http://www.space.com/missionlaunches/dart_prelaunc h_041025.html/

Re:How much of the artwork is wonder lust?

[Tablizer]

As an amature space artist myself (see http://www.geocities.com/astroviews/), I think I can comment on some of these.

At first I wondered if daylight would be that bright on Titan.

"Bright" is relative. I would very roughly guess that the light that reaches the surface is a little bit brighter than as that given by a full-moon on earth. If your eyes are dark-adjusted, you would be able to see surface features in reasonable detail I assume.

One image (Probe over Titan) shows Saturn getting light from a direction low on Titan's horizon, and yet there seems to be a bright halo around a dark cloud overhead, as if the sun were behind it.

I am not sure which rendering you are refering to, but I did not spot anything too odd. The light-pattern in the clouds may depend on their thickness, and the thickness may be variable. Thus, the clouds may be bright in some spots and dim in others based on their blotchiness pattern alone.

Also, their reflectivity characteristics may be different than those on Earth because they are not water-vapor clouds. Note how the sky is orangish on Mars during high-noon, but blue near a sunset, yet reverse on the earth. Things may look out-of-whack on Titan.

One thing that does stand out as contrived is how easily Saturn is visable. The Voyager probes could not see any surface, so more likely the reverse is also true: you can't see distinct features above the clouds, such as Saturn.

Perhaps every now and then the clouds part enough that a hazy Saturn could be seen. Or, the artist could just claim that a special filter is being used to view the scene. Cassini has just such a filter to view the surface.

Another thing, the sky would likely be brighter than the surface, as is usually the case with amorphous (clouded) light. Except if the cloud cover is uneven, then there could be brighter spots on the ground from time-to-time as "holes" allow more light in at times.

But any such art peices should be taken with a grain of salt. Nobody has been there before, so it is all just an educated guess.